1. Field of the Invention
This invention relates to a tape cartridge and a recording/reproduction apparatus for the tape cartridge and, more particularly to, a small-scale tape cartridge having a two- or three-lids structure in which a pocket or mouth portion, for receiving a head of the recording/reproduction apparatus upon loading of the cartridge in the recording/reproduction apparatus, is formed in a front portion of a casing body of the tape cartridge, and in which a tape of the tape cartridge extending across the pocket portion is covered with the two or three lids when the cartridge is not loaded.
With respect to tape cartridges described in this specification, "front side" denotes a side of the tape cartridge facing the head, "upper side" denotes a side of the cartridge where the lids are positioned when opened, "transverse end", "side" and "left and/or right" correspond to an end portion or portions of the pocket portion located oppositely in a longitudinal direction of the tape extending in the pocket portion.
2. Description of Related Art
A conventional double-lid or two-lid structure of tape cartridges of the aforementioned type, e.g., an 8 mm video tape cartridge, as shown in FIG. 19, has a front lid 202 capable of opening and closing a front side of a pocket 201, and an inner lid or back or rear lid 205 capable of opening and closing a non-magnetic surface side of a magnetic tape 204 by moving along guide grooves 203 in side walls of the pocket 201. See, for example, Japanese Patent Unexamined Publication Nos. 58-128069, 61-210585 and 61-210587.
Further, in order to reduce the size of a recording/reproduction mechanism or apparatus for such a tape cartridge, a conventional cylinder/cartridge overlapping system, as shown in FIG. 20, includes a cylindrical head or cylinder, with the read/write head 206 of the recording/reproduction apparatus entering the pocket 201 of the cartridge at the time of cartridge loading. See, for example, Japanese Patent Laid-Open Publication Nos. 60-163264 and 60-171684.
In the last-mentioned construction, if the cylinder (cylinder drum) 206 is introduced deep into the pocket of the 8 mm video cartridge to an excessively large extent, there is a possibility that the cylinder 206 may interface with a part of the inner or back lid 205, for opening/closing the non-magnetic face side of the tape 204, as shown in FIG. 20.
Recently, various technologies have been developed to meet a demand for magnetic recording/reproduction apparatuses such as video cameras (VTRs, i.e., video tape recorders and/or players) smaller in size and weight. In general, the size of a VTR mechanism is determined by shapes of the cylinder and the tape cartridge (cassette). Accordingly, for reduction in the size of the mechanism, it is necessary to reduce the size(s) of the cylinder and/or the cartridge. Therefore, attempts have been made to reduce the diameter of the cylinder by increasing the rotational speed and/or increasing the tape winding angle and other measures and to develop a compact cassette (cartridge) having an external size smaller than that of the digital audio tape (DAT) cassette. It is desirable to solve beforehand the above-mentioned problem of contact or interference between the cylinder and the inner lid so as to enable use of such a new cartridge.
In a conventional tape cartridge as shown in FIGS. 19 and 20, the inner lid 205 having an upper lid portion 207 serving as an upper lid and a back lid portion 208 serving as a back lid is brought into substantial contact with an upper surface 210 of a cartridge casing body 209, when the inner lid 205 is in an open state shown in FIG. 20. Accordingly, a cartridge pressing portion 212 of the transport or transfer means 211, which moves the tape cartridge in a direction of the arrow A to a predetermined position in the recording/reproduction apparatus at the time of loading of the cartridge in the apparatus, presses the casing body 209 in the direction of the arrow A at a position thereof on the back or rear side (in a direction of the arrow B) of the inner lid 205 set in the open position.
However, it has been determined that there is a risk of failure to appropriately press the cartridge casing body 209 in the direction of the arrow A by such pressing if the cartridge is smaller.
Japanese Patent Examined Publication No. 63-16825 discloses a triple-lid type of tape cartridge in which, as shown in FIG. 21, front and back surfaces of a tape 204 are covered with a front lid 215 and a back lid 216 while an upper side of a pocket 201 is covered with an upper lid 217. The front lid 215 moves upwardly around pivot 218 to upwardly open relative to a casing body 209. The upper lid 217 is connected to the front lid 215 by connecting pins 219. The upper lid 217 is moved obliquely upwardly to move onto an upper surface 210 of the casing body 209 in response to the upward pivotal movement of the front lid 215. The back lid 216 is connected to the upper lid 217 by connecting pins 220. Slide pins 221 provided on lower wall portions of the back lid 216 are moved and guided along guide grooves 222 in side walls of the pocket 201. In the open state of the lids 215, 216, 217, the back lid 216 is moved above the pocket 201 to the upper surface 210 of the casing body 209 to be laid generally parallel to the upper surface 210.
In a structure having three members, i.e., front lid 215, back lid 216 and upper lid 217 pivotally connected to each other in this manner, the lids 215, 216, and 217 retract in such a manner so as to be laid upon each other in the open state. In this manner, the amount of forward projection of the cover lids 205 to 207 at the upper positions in the open state can be reduced. However, a front end 223 of the back lid 216 is positioned so as to cover an upper portion of the pocket 201. Therefore, a compact component arrangement cannot be adopted in which the magnetic head of the tape recording/reproduction apparatus is introduced deep into the pocket 201. Accordingly, the effect of reducing the overall size of the recording/reproduction apparatus is limited.
Also in the case of the conventional tape cartridge constructed as shown in FIG. 21, the upper lid 217 is brought into contact with the upper surface 210 of the casing body 209, and a cartridge pressing portion of a cartridge transport or transfer means should therefore be adapted to press the casing body 209 at the back or rear side, i.e., in the direction of the arrow B, of the upper lid 217 in the open state.
When the tape cartridge of FIG. 21 is in the lids-closing state, left and right side ends of the back lid 216 are supported at four points through the upper connecting pins 220 and the lower slide pins 221, where a wall portion 231 of the back lid 216 has a shape of longer dimension or size in the widthwise direction of the cartridge and shorter dimension or size in the direction of thickness of the cartridge.
Therefore, if an external force in the direction of the arrow C is applied to the back lid 216 so as to press the back lid 216 obliquely upwardly, for example, by an inadvertent operation of a user, the wall portion 231 of the back lid 216 is deformed in a flexural manner toward the front of the casing body 209, as indicated by an imaginary or double-dot-dash line in FIG. 22. In such a case, there is a possibility that the connecting pin(s) 220 will come off the associated pin hole(s) with the deformation of the lid wall 231.
To avoid such a situation, it has been considered to increase the axial length of the connecting pins 220 and the depth of the associated pin holes fitted around that connecting pins 220. In practice, however, the operation of assembling these components becomes difficult if an engagement structure having an increased fitting depth is adopted.